Goal

Use reported cases to estimate actual infections

• For every US state
• Between March 1, 2020 to January 1, 2022
• Provide an “authoritative” estimate with uncertainty
• No compartmental models, no sampling or Bayesian methods

Retrospective deconvolution

• Based on prior work (Jahja et al. 2021)
• Take reported cases and deconvolve them to find when symptoms began
• Private CDC linelist to estimate the delay from symptom onset to case report
  • Different delay distribution for every report date and state
• Combine with Literature estimate of the delay from infection to symptom onset
  • Variant specific
  • Prevailing variant mix taken from GISAID
• Convolve both to get delay distribution from infection to case report

Empirical delay distributions

need this data.

Variant mix

Need this data.

Incubation period by state

Convolved distribution – Infection to case report

Cases are selectively reported to CDC

• CDC linelist with both onset and report date
• Shrink the parameters to national proportionally

Some deconvolution math

Deconvolve cases by their delay distribution

Estimate the inverse reporting ratio

Serology data

State space model

Results

Callouts